Patient interface

ABSTRACT

A patient interface for delivery of a supply of pressurised air or breathable gas to an entrance of a patient&#39;s airways includes a frame member, a cushion assembly provided to the frame member, and an anterior wall member repeatedly engageable with and disengageable from the cushion assembly. The frame member includes connectors operatively attachable to a positioning and stabilizing structure. The cushion assembly includes a seal-forming structure and a void defined by an anterior surface of the cushion assembly. The anterior wall member has a predetermined surface area to seal the void of the cushion assembly and form a gas chamber when the anterior wall member and the cushion assembly are engaged. The void of the cushion assembly is sized such that the patient&#39;s nose and/or mouth is substantially exposed when the anterior wall member is disengaged from the cushion assembly thereby improving breathing comfort of the patient.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/926,936, filed Jul. 13, 2020, which is a continuation of U.S.application Ser. No. 16/270,731, filed Feb. 8, 2019, now U.S. Pat. No.10,744,293, which is a continuation of U.S. application Ser. No.14/717,238, filed May 20, 2015, now U.S. Pat. No, 10,232,137, whichclaims the benefit of U.S. Provisional Patent Application No.62/001,944, filed May 22, 2014, each of which is incorporated herein byreference in its entirety.

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

1 (A) BACKGROUND OF THE TECHNOLOGY 1.1 (1) Field of the Technology

The present technology relates to one or more of the diagnosis,treatment and amelioration of respiratory disorders, and to proceduresto prevent respiratory disorders. In particular, the present technologyrelates to medical devices, and their use for treating respiratorydisorders and for preventing respiratory disorders.

1.2 (2) Description of the Related Art

The respiratory system of the body facilitates gas exchange. The noseand mouth form the entrance to the airways of a patient.

The airways include of a series of branching tubes, which becomenarrower, shorter and more numerous as they penetrate deeper into thelung. The prime function of the lung is gas exchange, allowing oxygen tomove from the air into the venous blood and carbon dioxide to move out.The trachea divides into right and left main bronchi, which furtherdivide eventually into terminal bronchioles. The bronchi make up theconducting airways, and do not take part in gas exchange. Furtherdivisions of the airways lead to the respiratory bronchioles, andeventually to the alveoli. The alveolated region of the lung is wherethe gas exchange takes place, and is referred to as the respiratoryzone. See West, Respiratory Physiology—the essentials.

A range of respiratory disorders exist.

Obstructive Sleep Apnea (OSA), a form of Sleep Disordered Breathing(SDB), is characterized by occlusion of the upper air passage duringsleep. It results from a combination of an abnormally small upper airwayand the normal loss of muscle tone in the region of the tongue, softpalate and posterior oropharyngeal wall during sleep. The conditioncauses the affected patient to stop breathing for periods typically of30 to 120 seconds duration, sometimes 200 to 300 times per night. Itoften causes excessive daytime somnolence, and it may causecardiovascular disease and brain damage. The syndrome is a commondisorder, particularly in middle aged overweight males, although aperson affected may have no awareness of the problem. See U.S. Pat. No.4,944,310 (Sullivan).

Cheyne-Stokes Respiration (CSR) is a disorder of a patient's respiratorycontroller in which there are rhythmic alternating periods of waxing andwaning ventilation, causing repetitive de-oxygenation and re-oxygenationof the arterial blood. It is possible that CSR is harmful because of therepetitive hypoxia. In some patients CSR is associated with repetitivearousal from sleep, which causes severe sleep disruption, increasedsympathetic activity, and increased afterload. See U.S. Pat. No.6,532,959 (Berthon-Jones).

Obesity Hyperventilation Syndrome (OHS) is defined as the combination ofsevere obesity and awake chronic hypercapnia, in the absence of otherknown causes for hypoventilation. Symptoms include dyspnea, morningheadache and excessive daytime sleepiness.

Chronic Obstructive Pulmonary Disease (COPD) encompasses any of a groupof lower airway diseases that have certain characteristics in common.These include increased resistance to air movement, extended expiratoryphase of respiration, and loss of the normal elasticity of the lung.Examples of COPD are emphysema and chronic bronchitis. COPD is caused bychronic tobacco smoking (primary risk factor), occupational exposures,air pollution and genetic factors. Symptoms include: dyspnea onexertion, chronic cough and sputum production.

Neuromuscular Disease (NMD) is a broad term that encompasses manydiseases and ailments that impair the functioning of the muscles eitherdirectly via intrinsic muscle pathology, or indirectly via nervepathology. Some NMD patients are characterised by progressive muscularimpairment leading to loss of ambulation, being wheelchair-bound,swallowing difficulties, respiratory muscle weakness and, eventually,death from respiratory failure. Neuromuscular disorders can be dividedinto rapidly progressive and slowly progressive: (i) Rapidly progressivedisorders: Characterised by muscle impairment that worsens over monthsand results in death within a few years (e.g. Amyotrophic lateralsclerosis (ALS) and Duchenne muscular dystrophy (DMD) in teenagers);(ii) Variable or slowly progressive disorders: Characterised by muscleimpairment that worsens over years and only mildly reduces lifeexpectancy (e.g. Limb girdle, Facioscapulohumeral and Myotonic musculardystrophy). Symptoms of respiratory failure in NMD include: increasinggeneralised weakness, dysphagia, dyspnea on exertion and at rest,fatigue, sleepiness, morning headache, and difficulties withconcentration and mood changes.

Chest wall disorders are a group of thoracic deformities that result ininefficient coupling between the respiratory muscles and the thoraciccage. The disorders are usually characterised by a restrictive defectand share the potential of long term hypercapnic respiratory failure.Scoliosis and/or kyphoscoliosis may cause severe respiratory failure.Symptoms of respiratory failure include: dyspnea on exertion, peripheraloedema, orthopnoea, repeated chest infections, morning headaches,fatigue, poor sleep quality and loss of appetite.

Otherwise healthy individuals may take advantage of systems and devicesto prevent respiratory disorders from arising.

1.2.1 Systems

One known product used for treating sleep disordered breathing is the S9Sleep Therapy System, manufactured by ResMed.

1.2.2 Therapy

Nasal Continuous Positive Airway Pressure (CPAP) therapy has been usedto treat Obstructive Sleep Apnea (OSA). The hypothesis is thatcontinuous positive airway pressure acts as a pneumatic splint and mayprevent upper airway occlusion by pushing the soft palate and tongueforward and away from the posterior oropharyngeal wall.

Non-invasive ventilation (NIV) has been used to treat OHS, COPD, MD andChest Wall disorders.

1.2.3 Patient Interface

The application of a supply of air at positive pressure to the entranceof the airways of a patient is facilitated by the use of a patientinterface, such as a nasal mask, full-face mask or nasal pillows. Arange of patient interface devices are known, however a number of themsuffer from being one or more of obtrusive, aesthetically undesirable,poorly fitting, difficult to use and uncomfortable, especially when wornfor long periods of time or when a patient is unfamiliar with a system.Masks designed solely for aviators, as part of personal protectionequipment or for the administration of anaesthetics may be tolerable fortheir original application, but nevertheless be undesirablyuncomfortable to be worn for extended periods, for example, whilesleeping.

1.2.3.1 Seal-Forming portion

Patient interfaces typically include a seal-forming portion.

One type of seal-forming portion extends around the periphery of thepatient interface, and is intended to seal against the user's face whenforce is applied to the patient interface with the seal-forming portionin confronting engagement with the user's face. The seal-forming portionmay include an air or fluid filled cushion, or a moulded or formedsurface of a resilient seal element made of an elastomer such as arubber. With this type of seal-forming portion, if the fit is notadequate, there will be gaps between the seal-forming portion and theface, and additional force will be required to force the patientinterface against the face in order to achieve a seal.

Another type of seal-forming portion incorporates a flap seal of thinmaterial so positioned about the periphery of the mask so as to providea self-sealing action against the face of the user when positivepressure is applied within the mask. Like the previous style of sealforming portion, if the match between the face and the mask is not good,additional force may be required to effect a seal, or the mask may leak.Furthermore, if the shape of the seal-forming portion does not matchthat of the patient, it may crease or buckle in use, giving rise toleaks.

Another form of seal-forming portion may use adhesive to effect a seal.Some patients may find it inconvenient to constantly apply and remove anadhesive to their face.

A range of patient interface seal-forming portion technologies aredisclosed in the following patent applications, assigned to ResMedLimited: WO 1998/004,310; WO 2006/074,513; WO 2010/135,785.

1.2.3.2 Positioning and Stabilising

A seal-forming portion of a patient interface used for positive airpressure therapy is subject to the corresponding force of the airpressure to disrupt a seal. Thus a variety of techniques have been usedto position the seal-forming portion, and to maintain it in sealingrelation with the appropriate portion of the face.

One technique is the use of adhesives. See for example US Patentpublication US 2010/0000534.

Another technique is the use of one or more straps and/or stabilisingharnesses. Many such harnesses suffer from being one or more ofill-fitting, bulky, uncomfortable and awkward to use.

1.2.3.3 Vent Technologies

Some forms of patient interface systems may include a vent to allow thewashout of exhaled carbon dioxide. Many such vents are noisy. Others mayblock in use and provide insufficient washout. Some vents may bedisruptive of the sleep of a bed-partner 1100 of the patient 1000, e.g.through noise or focussed airflow.

ResMed Limited has developed a number of improved mask venttechnologies. See WO 1998/034,665; WO 2000/078,381; U.S. Pat. No.6,581,594; US Patent Application; US 2009/0050156; US Patent Application2009/0044808.

Table of noise of prior masks (ISO 17510-2:2007, 10 cmH₂O pressure at 1m)

A-weighted A-weighted sound power sound level dbA pressure dbA Year Maskname Mask type (uncertainty) (uncertainty) (approx.) Glue-on (*) nasal50.9 42.9 1981 ResCare standard (*) nasal 31.5 23.5 1993 ResMed Mirage(*) nasal 29.5 21.5 1998 ResMed UltraMirage nasal 36 (3) 28 (3) 2000ResMed Mirage Activa nasal 32 (3) 24 (3) 2002 ResMed Mirage Micro nasal30 (3) 22 (3) 2008 ResMed Mirage SoftGel nasal 29 (3) 22 (3) 2008 ResMedMirage FX nasal 26 (3) 18 (3) 2010 ResMed Mirage Swift (*) nasal pillows37   29   2004 ResMed Mirage Swift II nasal pillows 28 (3) 20 (3) 2005ResMed Mirage Swift LT nasal pillows 25 (3) 17 (3) 2008 ResMed Mirageseries I, II (*) full face 31.7 23.7 2000 ResMed UltraMirage full face35 (3) 27 (3) 2004 ResMed Mirage Quattro full face 26 (3) 18 (3) 2006ResMed Mirage Quattro FX full face 27 (3) 19 (3) 2008 (* one specimenonly, measured using test method specified in ISO3744 in CPAP mode at 10cmH₂O)

Sound pressure values of a variety of objects are listed below

A-weighted sound pressure dbA Object (uncertainty) Notes Vacuum cleaner:Nilfisk Walter 68 ISO3744 at 1 m Broadly Litter Hog: B+ Grade distanceConversational speech 60 1 m distance Average home 50 Quiet library 40Quiet bedroom at night 30 Background in TV studio 20

1.2.3.4 Nasal Pillow Technologies

One form of nasal pillow is found in the Adam Circuit manufactured byPuritan Bennett. Another nasal pillow, or nasal puff is the subject ofU.S. Pat. No. 4,782,832 (Trimble et al.), assigned to Puritan-BennettCorporation.

ResMed Limited has manufactured the following products that incorporatenasal pillows: SWIFT nasal pillows mask, SWIFT II nasal pillows mask,SWIFT LT nasal pillows mask, SWIFT FX nasal pillows mask and LIBERTYfull-face mask. The following patent applications, assigned to ResMedLimited, describe nasal pillows masks: International Patent ApplicationWO 2004/073,778 (describing amongst other things aspects of ResMed SWIFTnasal pillows), US Patent Application 2009/0044808 (describing amongstother things aspects of ResMed SWIFT LT nasal pillows); InternationalPatent Applications WO 2005/063,328 and WO 2006/130,903 (describingamongst other things aspects of ResMed LIBERTY full-face mask);International Patent Application WO 2009/052,560 (describing amongstother things aspects of ResMed SWIFT FX nasal pillows).

2 (B) BRIEF SUMMARY OF THE TECHNOLOGY

The present technology is directed towards providing medical devicesused in the diagnosis, amelioration, treatment, or prevention ofrespiratory disorders having one or more of improved comfort, cost,efficacy, ease of use and manufacturability.

One aspect of the present technology relates to apparatus used in thediagnosis, treatment or prevention of a respiratory disorder.

Another aspect of the present technology relates to apparatus fortreating a respiratory disorder including a patient interface, an aircircuit, and a source of air at positive pressure.

Another aspect of the present technology relates to methods used in thediagnosis, treatment or prevention of a respiratory disorder.

Another aspect of the present technology relates to a patient interfacefor sealed delivery of a flow of breathable gas at a continuouslypositive pressure with respect to ambient air pressure to an entrance tothe patient's airways including at least entrance of a patient's nares,wherein the patient interface is configured to maintain a therapypressure in a range of about 4 cmH₂O to about 30 cmH₂O above ambient airpressure in use, throughout the patient's respiratory cycle, while thepatient is sleeping, to ameliorate sleep disordered breathing. In anexample, the patient interface includes a cushion assembly including aseal-forming structure adapted to form a seal against the patient'sairways and a plenum chamber pressurised at a pressure above ambientpressure in use, a positioning and stabilising structure to maintain thecushion assembly in sealing contact with an area surrounding an entranceto the patient's airways while maintaining a therapeutic pressure at theentrance to the patient's airways, a gas washout vent configured toallow a flow of patient exhaled CO₂ to an exterior of the patientinterface to minimise rebreathing of exhaled CO₂ by the patient, and aframe assembly to releasably engage the cushion assembly and provide aconnection to the positioning and stabilising structure.

Another aspect of the present technology relates to a patient interfacehaving improved comfort by reducing apparent bulk/obtrusiveness of thepatient interface, reducing the claustrophobic (enclosed) feeling of thepatient interface and/or providing a patient interface that allows thepatient to feel more in control of their therapy.

Another aspect of the present technology relates to a patient interfaceincluding a repeatedly engageable/disengageable anterior wall member orfascia that allows the patient's nose and/or mouth to be substantiallyexposed when disengaged to improve breathing comfort of the patient(e.g., minimal breathing obstruction). Such arrangement providesimproved breathing comfort when therapy is not required and does notrequire the patient to adjust the headgear or the cushion seal since thepatient interface remains on the patient's head when the fascia isdisengaged or removed. Such arrangement provides less bulk on thepatient's face (facial footprint area and weight) when therapy is notrequired, when the patient has removed the fascia. Also, sucharrangement may allow automatic start/stop of pressurised air to thepatient interface upon detection of fascia engagement/disengagement,therefore minimizing waste of pressurised air when therapy is notrequired. Removal of the fascia may also improve patient communicationwith the bed partner (e.g., no muffled voice and ability for bed partnerto clearly view the patient's mouth), allow the patient todrink/eat/medicate without having to completely remove the patientinterface, allow the clinician to view and assess the cushion seal onthe patient's face, optimize gas washout, facilitate patient/clinicianacclimatization to CPAP therapy (e.g., training-type patient interface),and/or provide a means for patient to disconnect patient interface fromthe flow generator (e.g., to go to the bathroom throughout the night).

In an example, the cushion assembly and the anterior wall member(fascia) are structured to maintain engagement during use and preventany unintentional or partial disassembly during use, e.g., caused bytube drag forces. In an example, the anterior wall members sealinglyengages the cushion assembly, e.g., to prevent leak. In an example, theanterior wall member and cushion assembly provide an easy/intuitivearrangement for assembly/disassembly (e.g., assembly/disassembly withoutinstruction), which requires minimal dexterity (e.g., one-handedoperation). In an example, assembly/disassembly of the anterior wallmember to the cushion assembly may require less than about 6N force. Inan example, audible, tactile and/or visual feedback may be provided uponcorrect assembly of the anterior wall member to the cushion assembly.

Another aspect of the present technology relates to a patient interfacearrangement for treatment of sleep disordered breathing that may allowautomatic start/stop of pressurised air to the patient interface upondetection of engagement/disengagement (e.g., via magnetic sensors) of afascia, elbow and/or gas delivery tube, therefore minimizing waste ofpressurised air when therapy is not required.

Another aspect of the present technology relates to a patient interfacefor delivery of a supply of pressurised air or breathable gas to anentrance of a patient's airways including a frame member, a cushionassembly provided to the frame member, and an anterior wall memberrepeatedly engageable with and disengageable from the cushion assembly.The frame member includes connectors operatively attachable to apositioning and stabilizing structure. The cushion assembly includes aseal-forming structure and a void defined by an anterior surface of thecushion assembly. The anterior wall member has a predetermined surfacearea to seal the void of the cushion assembly and form a gas chamberwhen the anterior wall member and the cushion assembly are engaged. Thevoid of the cushion assembly is sized such that the patient's noseand/or mouth is substantially exposed when the anterior wall member isdisengaged from the cushion assembly thereby improving breathing comfortof the patient.

Another aspect of the present technology relates to a method of donninga patient interface for delivery of a supply of pressurised air orbreathable gas to an entrance of a patient's airways, the methodincluding providing a frame member including connectors to a cushionassembly including a seal-forming structure and a void defined by ananterior surface of the cushion assembly, positioning the cushionassembly against the patient's face using a positioning and stabilizingstructure operatively attached to the frame member, and engaging ananterior wall member having a predetermined surface area with thecushion assembly to seal the void of the cushion assembly and form a gaschamber when the anterior wall member and the cushion assembly aresealingly engaged, the anterior wall member comprising a connection portfor connection to a gas delivery tube, wherein the void of the cushionassembly is sized such that the patient's nose and/or mouth issubstantially exposed to ambient air when the anterior wall member isdisengaged from the cushion assembly.

Another aspect of the present technology relates to a patient interfacefor sealed delivery of a flow of breathable gas at a continuouslypositive pressure with respect to ambient air pressure to an entrance tothe patient's airways including at least entrance of a patient's nares,wherein the patient interface is configured to maintain a therapypressure in a range of about 4 cmH₂O to about 30 cmH₂O above ambient airpressure in use, throughout the patient's respiratory cycle, while thepatient is sleeping, to ameliorate sleep disordered breathing. Thepatient interface includes a cushion assembly including a seal-formingstructure adapted to form a seal against the patient's airways, apositioning and stabilising structure to maintain the cushion assemblyin sealing contact with an area surrounding an entrance to the patient'sairways while maintaining a therapeutic pressure at the entrance to thepatient's airways, a frame member to engage the cushion assembly andprovide a connection to the positioning and stabilising structure, thecushion assembly including a void defined by an anterior surface of thecushion assembly, and an anterior wall member repeatedly engageable withand disengageable from the cushion assembly. The anterior wall memberhas a predetermined surface area to seal the void of the cushionassembly and form a gas chamber when the anterior wall member and thecushion assembly are engaged. The anterior wall member and the cushionassembly are magnetically engageable.

Another aspect of the present technology relates to a patient interfacefor sealed delivery of a flow of breathable gas at a continuouslypositive pressure with respect to ambient air pressure to an entrance tothe patient's airways including at least entrance of a patient's nares,wherein the patient interface is configured to maintain a therapypressure in a range of about 4 cmH₂O to about 30 cmH₂O above ambient airpressure in use, throughout the patient's respiratory cycle, while thepatient is sleeping, to ameliorate sleep disordered breathing. Thepatient interface includes a cushion assembly including a seal-formingstructure adapted to form a seal against the patient's airways, apositioning and stabilising structure to maintain the cushion assemblyin sealing contact with an area surrounding an entrance to the patient'sairways while maintaining a therapeutic pressure at the entrance to thepatient's airways, a frame member to engage the cushion assembly andprovide a connection to the positioning and stabilising structure, theframe member including a void defined by an anterior surface of theframe member, and an anterior wall member repeatedly engageable with anddisengageable from the frame member. The anterior wall member has apredetermined surface area to seal the void of the frame member and forma gas chamber when the anterior wall member and the frame member areengaged. The anterior wall member and the frame member are magneticallyengageable.

Another aspect of the present technology relates to a patient interfacefor sealed delivery of a flow of breathable gas at a continuouslypositive pressure with respect to ambient air pressure to an entrance tothe patient's airways including at least entrance of a patient's nares,wherein the patient interface is configured to maintain a therapypressure in a range of about 4 cmH₂O to about 30 cmH₂O above ambient airpressure in use, throughout the patient's respiratory cycle, while thepatient is sleeping, to ameliorate sleep disordered breathing. Thepatient interface includes a frame member including connectorsoperatively attachable to a positioning and stabilizing structure, acushion assembly provided to the frame member, an anterior wall memberrepeatedly engageable with and disengageable from the cushion assembly,and a detachable heat and moisture exchanger (HME/HMX) cartridge. Thecushion assembly includes a seal-forming structure and a void defined byan anterior surface of the cushion assembly. The anterior wall memberhas a predetermined surface area to seal the void of the cushionassembly and form a gas chamber when the anterior wall member and thecushion assembly are engaged. The HME/HMX cartridge is positioned withinthe gas chamber. The HME/HMX cartridge has a length greater than 22 mm.The anterior wall member has a length at least the same as the length ofthe HME/HMX cartridge to allow the HME/HMX cartridge to be detached viathe void defined by the anterior surface of the cushion assembly.

Of course, portions of the aspects may form sub-aspects of the presenttechnology. Also, various ones of the sub-aspects and/or aspects may becombined in various manners and also constitute additional aspects orsub-aspects of the present technology.

Other features of the technology will be apparent from consideration ofthe information contained in the following detailed description,abstract, drawings and claims.

(C) BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The present technology is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings, in whichlike reference numerals refer to similar elements including:

2.1 Treatment Systems

FIG. 1 a shows a system in accordance with the present technology. Apatient 1000 wearing a patient interface 3000, receives a supply of airat positive pressure from a PAP device 4000. Air from the PAP device ishumidified in a humidifier 5000, and passes along a gas delivery tube4170 to the patient 1000.

FIG. 1 b shows a PAP device in use on a patient with a nasal mask.

FIG. 1 c shows a PAP device in use on a patient with a full-face mask.

2.2 Therapy

2.2.1 Respiratory system

FIG. 2 a shows an overview of a human respiratory system including thenasal and oral cavities, the larynx, vocal folds, oesophagus, trachea,bronchus, lung, alveolar sacs, heart and diaphragm.

FIG. 2 b shows a view of a human upper airway including the nasalcavity, nasal bone, lateral nasal cartilage, greater alar cartilage,nostril, lip superior, lip inferior, larynx, hard palate, soft palate,oropharynx, tongue, epiglottis, vocal folds, oesophagus and trachea.

2.2.2 Facial Anatomy

FIG. 2 c is a front view of a face with several features of surfaceanatomy identified including the lip superior, upper vermillion, lowervermillion, lip inferior, mouth width, endocanthion, a nasal ala,nasolabial sulcus and cheilion.

FIG. 2 d is a side view of a head with several features of surfaceanatomy identified including glabella, sellion, pronasale, subnasale,lip superior, lip inferior, supramenton, nasal ridge, otobasion superiorand otobasion inferior. Also indicated are the directions superior &inferior, and anterior & posterior.

FIG. 2 e is a further side view of a head. The approximate locations ofthe Frankfort horizontal and nasolabial angle are indicated.

FIG. 2 f shows a base view of a nose.

FIG. 2 g shows a side view of the superficial features of a nose.

FIG. 2 h shows subcutaneal structures of the nose, including lateralcartilage, septum cartilage, greater alar cartilage, lesser alarcartilage and fibrofatty tissue.

FIG. 2 i shows a medial dissection of a nose, approximately severalmillimeters from a sagittal plane, amongst other things showing theseptum cartilage and medial crus of greater alar cartilage.

FIG. 2 j shows a front view of the bones of a skull including thefrontal, temporal, nasal and zygomatic bones. Nasal concha areindicated, as are the maxilla, mandible and mental protuberance.

FIG. 2 k shows a lateral view of a skull with the outline of the surfaceof a head, as well as several muscles. The following bones are shown:frontal, sphenoid, nasal, zygomatic, maxilla, mandible, parietal,temporal and occipital. The mental protuberance is indicated. Thefollowing muscles are shown: digastricus, masseter sternocleidomastoidand trapezius.

FIG. 2 l shows an anterolateral view of the nose and skull, includingbone and cartilaginous structures.

2.3 PAP Device and Humidifier

FIG. 3 a shows an exploded view of a PAP device according to an exampleof the present technology.

FIG. 3 b shows a perspective view of a humidifier in accordance with oneform of the present technology.

FIG. 3 c shows a schematic diagram of the pneumatic circuit of a PAPdevice in accordance with one form of the present technology. Thedirections of upstream and downstream are indicated.

2.4 Patient Interface

FIG. 4 is a perspective view of a patient interface shown on a patient'shead according to an example of the present technology, the patientinterface being shown with a removable anterior wall member engaged withthe cushion assembly.

FIG. 5 is a front view of the patient interface shown in FIG. 4 .

FIG. 6 is a side view of the patient interface shown in FIG. 4 .

FIG. 7 is a perspective view of a patient interface shown on a patient'shead according to an example of the present technology, the patientinterface being shown with the anterior wall member disengaged andremoved from the cushion assembly.

FIG. 8 is a front view of the patient interface shown in FIG. 7 .

FIG. 9 is a side view of the patient interface shown in FIG. 7 .

FIG. 10 is a perspective view of a patient interface according to anexample of the present technology, the patient interface being shownwith the anterior wall member engaged with the cushion assembly.

FIG. 11 a is an exploded view of the patient interface shown in FIG. 10.

FIG. 11 b is another exploded view of the patient interface shown inFIG. 10 showing the frame member engaged with the cushion assembly andthe anterior wall member disengaged and removed from the cushionassembly.

FIG. 12 is a front view of the patient interface shown in FIG. 10 .

FIG. 13 is a front view of the patient interface shown in FIG. 10 , thepatient interface being shown with a swivel elbow disengaged from theanterior wall member.

FIG. 14 is a front view of a frame member and cushion assembly of apatient interface shown in FIG. 10 .

FIG. 15 is a front view of an anterior wall member and a swivel elbow ofa patient interface shown in FIG. 10 .

FIG. 16 is a rear perspective view of the anterior wall member and theswivel elbow shown in FIG. 15 .

FIG. 17 is a side view showing the act of engaging an anterior wallmember with a cushion assembly of a patient interface shown on apatient's head according to an example of the present technology.

FIG. 18 is a side view showing the act of engaging an anterior wallmember with a cushion assembly of a patient interface shown on apatient's head according to another example of the present technology.

FIGS. 19 a and 19 b are side views showing the act of engaging ananterior wall member with a cushion assembly of a patient interfaceaccording to an example of the present technology.

FIG. 19 c is a schematic top view showing the act of engaging ananterior wall member with a cushion assembly of a patient interfaceaccording to an example of the present technology.

FIG. 20 a is a cross-sectional view of a patient interface according toan example of the present technology, the patient interface being shownwith the anterior wall member engaged with the cushion assembly.

FIG. 20 b is an exploded cross-sectional view of the patient interfaceshown in FIG. 20 a showing the anterior wall member disengaged from thecushion assembly.

FIG. 21 is a cross-sectional view of a patient interface according to anexample of the present technology, the patient interface being shownwith the anterior wall member disengaged from the cushion assembly toshow the size of the opening provided by the cushion assembly.

FIG. 22 is a cross-sectional view of a patient interface including acushion assembly without a disengageable anterior wall member to showthe size of the opening provided by the cushion assembly.

FIG. 23 is an exploded perspective view of a patient interface accordingto another example of the present technology.

FIG. 24 a is an exploded perspective view of a patient interfaceaccording to another example of the present technology.

FIG. 24 b is an exploded plan view of the patient interface of FIG. 24 aaccording to an example of the present technology.

FIG. 25 a is an exploded perspective view of a patient interfaceaccording to another example of the present technology.

FIG. 25 b is an exploded plan view of the patient interface of FIG. 25 aaccording to an example of the present technology.

FIG. 26 a is an exploded perspective view of a patient interfaceaccording to another example of the present technology.

FIG. 26 b is an exploded plan view of the patient interface of FIG. 26 aaccording to an example of the present technology.

FIG. 27 is an exploded plan view of a patient interface according toanother example of the present technology.

FIG. 28 is an exploded plan view of a patient interface according toanother example of the present technology.

FIG. 29 is an exploded plan view of the patient interface of FIG. 26according to an example of the present technology.

FIG. 30 is an exploded view of a patient interface according to anexample of the present technology showing the anterior wall memberdisengaged and removed from the cushion assembly.

FIG. 31 is a perspective view of a patient interface according toanother example of the present technology, the patient interface beingshown with the anterior wall member engaged with the cushion assembly.

FIG. 32 is an exploded view of the patient interface shown in FIG. 31 .

FIG. 33 is another exploded view of the patient interface shown in FIG.31 showing the frame member engaged with the cushion assembly and theanterior wall member disengaged and removed from the cushion assembly.

FIG. 34 is a perspective view of a patient interface according toanother example of the present technology, the patient interface beingshown with the anterior wall member engaged with the cushion assembly.

FIG. 35 is an exploded view of the patient interface shown in FIG. 34 .

FIG. 36 is another exploded view of the patient interface shown in FIG.34 showing the frame member engaged with the cushion assembly and theanterior wall member disengaged and removed from the cushion assembly.

FIG. 37 is a front view of the patient interface shown in FIG. 34 shownon a patient's head according to an example of the present technology,the patient interface being shown with the anterior wall memberdisengaged and removed from the cushion assembly.

FIG. 38 is an exploded view of the patient interface shown in FIG. 34showing assembly of the cushion assembly and the anterior wall member.

FIG. 39 is an enlarged cross-section view showing a lip seal of thecushion assembly according to an example of the present technology.

FIG. 40 is a perspective view of the anterior wall member of the patientinterface shown in FIG. 34 .

FIG. 41 is a cross-sectional view of the patient interface shown in FIG.34 showing engagement between the cushion assembly and the anterior wallmember.

FIG. 42 is a perspective view of a cushion assembly according to anotherexample of the present technology.

FIG. 43 is an exploded view of a patient interface according to anotherexample of the present technology.

FIG. 44 is a perspective view of the patient interface shown in FIG. 43showing the anterior wall member engaged with the cushion assembly.

FIG. 45 is a front view of the patient interface shown in FIG. 43 shownon a patient's head according to an example of the present technology,the patient interface being shown with the anterior wall memberdisengaged and removed from the cushion assembly.

FIG. 46 is an exploded view of the patient interface shown in FIG. 43showing assembly of the cushion assembly and the anterior wall member.

FIG. 47 is an exploded view of the patient interface shown in FIG. 43showing a mechanical interlock between the cushion assembly and theanterior wall member according to an example of the present technology.

FIG. 48 is a perspective view showing a common frame interface for themain body of a cushion assembly according to an example of the presenttechnology.

FIGS. 49A, 49B, and 49C are front views of small, medium, and largecushion assemblies according to an example of the present technology.

FIGS. 50A, 50B, and 50C are front views showing a common frame memberand a common anterior wall member engaged with each of the small,medium, and large cushion assemblies of FIGS. 49A, 49B, and 49Caccording to an example of the present technology.

FIGS. 51, 52, and 53 are cross-sectional views showing a retainingstructure of the cushion assembly according to an example of the presenttechnology.

3 (D) DETAILED DESCRIPTION OF EXAMPLES OF THE TECHNOLOGY

Before the present technology is described in further detail, it is tobe understood that the technology is not limited to the particularexamples described herein, which may vary. It is also to be understoodthat the terminology used in this disclosure is for the purpose ofdescribing only the particular examples discussed herein, and is notintended to be limiting.

The following description is provided in relation to several exampleswhich may share one or more common characteristics and features. It isto be understood that one or more features of any one example may becombinable with one or more features of another example or otherexamples. In addition, any single feature or combination of features inany of the examples may constitute a further example.

3.1 Treatment Systems

In one form, the present technology comprises an apparatus for treatinga respiratory disorder, as shown in FIGS. 1 a -1 c. The apparatus maycomprise a flow generator or blower 4000 for supplying pressurisedrespiratory gas, such as air, to the patient 1000 via a gas deliverytube 4170 leading to a patient interface 3000. The gas delivery tube4170 may be connected to an additional gas delivery tube 4180 by arotatable adapter 4190. A humidifier 5000 may also be provided tohumidify the gas. A bed partner 1100 may also be present with thepatient.

3.2 Therapy

In one form, the present technology comprises a method for treating arespiratory disorder comprising the step of applying positive pressureto the entrance of the airways of a patient 1000.

3.2.1 Nasal CPAP for OSA

In one form, the present technology comprises a method of treatingObstructive Sleep Apnea in a patient by applying nasal continuouspositive airway pressure to the patient.

3.3 Patient Interface

Referring to FIGS. 4 to 16 , a non-invasive patient interface 3000 inaccordance with one aspect of the present technology comprises a framemember 3100, a cushion assembly 3175 including a seal-forming structure3200, a removable anterior wall member 3300 (also referred to as aremovable fascia) repeatedly engageable with and removably disengageablefrom the cushion assembly 3175, and a positioning and stabilisingstructure 3400. In use, one form of the seal-forming structure 3200 isarranged to surround an entrance to the airways of the patient 1000 soas to facilitate the supply of air at positive pressure to the airways.The seal-forming structure 3200 (e.g., constructed of silicone) may alsobe commonly referred to as a cushion.

In one form of the present technology, the frame member 3100, thecushion assembly 3175, and the anterior wall member 3300 are repeatedlyand removably engageable with one another. In the illustrated example,the frame member 3100 and the cushion assembly 3175 are connected to oneanother, with the anterior wall member 3300 being repeatedly andremovably engageable with the cushion assembly 3175 (e.g., see FIG. 11 b). In this example, the anterior wall member 3300 is not directlyconnected to or engaged with the frame member 3100. In another example,the frame member and the cushion assembly may be connected to oneanother, with the anterior wall member being repeatedly and removablyengageable with the frame member (e.g., see FIG. 23 ). In this example,the cushion assembly is connected to the anterior wall member via theframe member, i.e., the cushion assembly is not directly connected tothe anterior wall member. In each form, the anterior wall member 3300 isalways removably engageable with the cushion assembly 3175 or framemember 3100.

The frame member 3100 (e.g., constructed of a relatively hard plasticmaterial such as polycarbonate) provides a connection between thecushion assembly 3175 and the positioning and stabilising structure3400, e.g., either in a removable fashion or a more permanent fashion,to allow sealing forces to be transferred to the cushion assembly 3175from the positioning and stabilising structure 3400.

The frame member 3100 may also be commonly referred to as a shroud,headgear connection structure, or chassis. In the illustrated example,the frame member 3100 engages with the cushion assembly 3175, andprovides a 4-point connection to the positioning and stabilisingstructure 3400. The anterior wall member 3300 comprises a multi-holevent 3700 surrounding connection port 3302. The connection port 3302 isconnected to an elbow or swivel elbow 3600, which is connected to thegas delivery tube 4180 for fluid communication with a gas chamber orplenum chamber 3500 of the patient interface 3000.

In one form of the present technology, the cushion assembly 3175includes a main body 3180 that is connected or otherwise provided to theseal-forming structure 3200. The main body 3180 may be permanently(e.g., co-molded, overmolded) or removably (e.g., mechanical interlock)connected to the seal-forming structure 3200. In an example, theseal-forming structure 3200 is constructed of a relatively flexible orpliable material (e.g., silicone) and the main body 3180 is constructedof a relatively rigid material (e.g., polycarbonate). In the illustratedexample, the cushion assembly 3175 includes a void 3102 defined by ananterior facing surface 3104 of the main body 3180 of the cushionassembly 3175. When the anterior wall member 3300 and the cushionassembly 3175 are engaged, the anterior wall member 3300 (also referredto as the fascia) has a predetermined surface area to pneumatically sealthe void 3102 of the cushion assembly 3175 and form the gas chamber orplenum chamber 3500 (e.g., see FIG. 20 a ). The predetermined surfacearea of the anterior wall member 3300 may be at least 50% of the totalsurface area of the superficial anterior wall of the cushion assembly3175. In an example, the predetermined surface area of the anterior wallmember 3300 may be greater than 381 mm². The void 3102 extends throughthe main body 3180 and the opening of the seal-forming structure 3200 toexpose the patient's mouth and/or nose and/or upper lip.

As best shown in FIGS. 7-9 and 21 , the void 3102 of the cushionassembly 3175 is sized such that the patient's nose and/or mouth issubstantially exposed to ambient air and visible to the bed partner 1100when the anterior wall member 3300 is disengaged from the cushionassembly 3175 thereby improving breathing comfort of the patient.Advantageously, this exposure may allow the bed partner 1100 to see thepatient's lips moving when speaking which is more humanizing. An idealbreathing comfort is ambient air external of the patient interface 3000which is considered natural breathing. Breathing comfort considersrelative humidity, quantity of carbon dioxide, air flow impedance andair temperature. When the patient interface 3000 is donned by thepatient and the anterior wall member 3300 is disengaged from the cushionassembly 3175 without therapy activated, breathing comfort for thepatient should be similar or substantially the same as breathing theambient air without the patient interface 3000 donned.

As shown in FIGS. 21 and 22 , the void 3102 is sized to be sufficientlylarger than a conventional connection port 302 for connection to a gasdelivery tube. A conventional connection port 302 typically has a 22 mmdiameter. That is, the void 3102 when the anterior wall member 3300 isremoved provides a larger mask opening than conventional masks when thegas delivery tube is removed from the conventional connection port 302.For example, the void 3102 provides a height H (FIG. 21 ) that issufficiently larger than a height or diameter h (22 mm) of theconventional connection port 302 (FIG. 22 ), which larger height Hallows the patient's nose and/or mouth to be substantially exposed whenthe anterior wall member 3300 is disengaged from the cushion assembly3175. In an example, the height or diameter H is greater than 22 mmand/or the void 3102 provides an area greater than 381 mm².

The sufficiently larger mask opening provided by the void 3102 improvesbreathing comfort of the patient (e.g., less claustrophobic, less airflow impedance), provides a less bulky/obtrusive mask (very lowprofile), allows visual inspection, better avoids condensation build-up(fogging), and/or assists with patient acclimatization of the patientinterface 3000.

The patient interface 3000 is structured to reduce bulk along thesagittal plane, i.e., reduce depth of the patient interface orprotrusion of the patient interface from the patient's face in theanterior-posterior direction. Also, the patient interface 3000 isstructured to reduce the facial footprint (the superficial surface area)in the coronal plane, i.e., the surface area projected by the patientinterface 3000 on the patient's face. The reduction in size in all threedimensions when the anterior wall member 3300 is removed from thecushion assembly 3175 reduces overall weight and perceived size andweight by the patient.

In an example, as shown in FIG. 20 b, the patient interface 3000 may bestructured to house an optional and replaceable heat and moistureexchanger (HME/HMX) cartridge 3750 to provide sufficient heat andhumidity to the patient during therapy. For example, the HME/HMXcartridge 3750 may be integrated or otherwise received and supported inthe anterior wall member 3300. In an example, the HME/HMX cartridge is adetachable HME/HMX cartridge positioned within the gas chamber andhaving a length greater than a diameter of a conventional connectionport, i.e., length greater than 22 mm. The anterior wall member 3300 mayhave a length at least the same as the length of the HME/HMX cartridgeto allow the HME/HMX cartridge to be detached via the void 3102 definedby the anterior surface of the cushion assembly 3175. Such arrangementallows a HME/HMX cartridge having a length greater than 22 mm to beremoved or inserted via the front of the patient interface.

Engagement between Cushion Assembly and Anterior Wall Member

In one form of the present technology, at least a peripheral portion3305 of the anterior wall member 3300 is repeatedly engageable with anddisengageable from at least a peripheral portion 3105 of the main body3180 of the cushion assembly 3175. In an example, the peripheral portion3305 of the anterior wall member 3300 and the peripheral portion 3105 ofthe cushion assembly 3175 are rigid such that engagement between theperipheral portion 3305 of the anterior wall member 3300 and theperipheral portion 3105 of the cushion assembly 3175 provides ahard-to-hard connection and is not caused by material deformation of thecushion assembly 3175 and/or the anterior wall member 3300.

In an example, the perimeter and/or shape of the anterior wall member3300 is predetermined to facilitate alignment of the anterior wallmember 3300 to the cushion assembly 3175 for mechanical/structuralengagement. For example, the shape of the anterior wall member 3300 maybe symmetrical in at least one axis to minimise misalignment of theanterior wall member 3300 to the cushion assembly 3175 for engagement.

In an example, when the cushion assembly 3175 and the anterior wallmember 3300 are engaged, accidental disengagement caused by tube dragforces is prevented due to the shape, geometry and perimeter of themating surfaces of the cushion assembly 3175 and the anterior wallmember 3300. That is, the cushion assembly 3175 and the anterior wallmember 3300 are structured to maintain engagement during use and preventany unintentional or partial disassembly during use.

Magnetic Engagement

In one form of the present technology, the anterior wall member 3300 ismagnetically engageable with the cushion assembly 3175. For example, theperipheral portion 3305 of the anterior wall member 3300 and theperipheral portion 3105 of the main body 3180 of the cushion assembly3175 may be magnetically engageable.

As shown in FIGS. 11 a and 11 b, the anterior facing surface 3104 (alsoreferred to as a mounting surface) provided along the exterior oroutwardly facing surface of the peripheral portion 3105 of the cushionassembly 3175 includes at least one magnet 3110, and the posteriorfacing surface 3303 provided along the interior or inwardly facingsurface of the peripheral portion 3305 of the anterior wall member 3300includes at least one magnet 3310.

In the example shown in FIGS. 4 to 16 , the cushion assembly 3175 andthe anterior wall member 3300 each include three magnets, e.g., onemagnet 3110, 3310 provided along an apex of the respective peripheralportion 3105, 3305 and the remaining two magnets 3110, 3310 provided onopposing, lower sides of the respective peripheral portion 3105, 3305.However, it should be appreciated that more or less magnets may beprovided, and the magnets 3110, 3310 may be positioned in other suitablearrangements and positions along the peripheral portions 3105, 3305. Themagnets 3110, 330 depicted have a circular cross-section, however, anyshape or size may be suitable.

In an example, the at least one magnet 3110, 3310 provided to thecushion assembly 3175 and the anterior wall member 3300 may be apermanent magnet or an electromagnet.

The magnetic attraction between the magnets 3110, 3310 of the cushionassembly 3175 and the anterior wall member 3300 guides and aligns theanterior wall member 3300 to the cushion assembly 3175 during engagementat least prior to surface contact between the cushion assembly 3175 andthe anterior wall member 3300 when they are in close physical proximityto each other. Also, the magnetic attraction between the anterior wallmember 3300 and the cushion assembly 3175 may provide the primaryengagement force to maintain engagement of the anterior wall member 3300to the cushion assembly 3175. In an example, the retention force (fromthe magnets) between the anterior wall member 3300 and the cushionassembly 3175 is less than the retention force (from headgear) tomaintain the cushion assembly 3175 in sealing engagement with thepatient's face.

The easy magnetic connection/disconnection between the cushion assembly3175 and the anterior wall member 3300 facilitates use in the dark usingmacro movement (e.g., useful for bathroom break during the night),provides easy access to the patient for hospital/lab use cases byproviding a quick release, and provides a greater sense of control overtherapy for the patient (quick release, e.g., without pressing anybuttons or rotating a bayonet coupling). Macro movement is contrastedwith fine motor skills.

Flow Generator Activation/Deactivation

In one form of the present technology, engagement of the anterior wallmember 3300 with the cushion assembly 3175 automatically activates aflow generator 4000 to supply pressurised respiratory gas to the patientinterface 3000 via a gas delivery tube 4180 connected to the elbow 3600,and disengagement of the anterior wall member 3300 from the cushionassembly 3175 automatically deactivates the flow generator 4000 to ceasethe supply of pressurised respiratory gas to the patient interface 3000.In another example, engagement of the anterior wall member 3300 with thecushion assembly 3175 automatically actuates a valve to activate thesupply of pressurised respiratory gas to the patient interface 3000.

For example, magnetic engagement of the peripheral portion 3305 of theanterior wall member 3300 to the peripheral portion 3105 of the cushionassembly 3175 causes the flow generator 4000 to supply pressurisedrespiratory gas to the patient interface 3000 via the gas delivery tube,and when the anterior wall member 3300 and cushion assembly 3175 aredisengaged, the flow generator ceases the supply of pressurisedrespiratory gas to the patient interface 3000.

An electrical activate/deactivate signal may be sent from the patientinterface 3000 to the flow generator 4000 in accordance with methods andapparatuses disclosed in U.S. Pat. No. 6,240,921, which is hereinincorporated by reference in its entirety.

If the gas delivery tube 4170 is a heated tube comprising at least onewire, the at least one wire may transmit an electricalactivate/deactivate signal from the patient interface 3000 to the flowgenerator 4000 to activate or cease the supply of pressurisedrespiratory gas to the patient interface 3000.

Alternatively, there may be a wireless transmitter located at thepatient interface 3000 which may wirelessly transmit an electricalactivate/deactivate signal to a wireless receiver located at the flowgenerator 4000 to activate or cease the supply of pressurisedrespiratory gas to the patient interface 3000.

The activate/deactivate signal may be sent upon detection of a magneticfield using a reed sensor, Hall Effect sensor or anisotropicmagnetoresistance (AMR) sensor.

Alternative Engagement Examples Between Anterior Wall Member and CushionAssembly

In an alternative example, the peripheral portion 3305 of the anteriorwall member 3300 and the peripheral portion 3105 of the cushion assembly3175 may be engageable using an adhesive or a hook-and-loop fastener.

In an alternative example, the peripheral portion 3305 of the anteriorwall member 3300 and the peripheral portion 3105 of the cushion assembly3175 may be engageable using a mechanical interlock, e.g., snap-fitconnection, barb, hinge, etc.

It should be appreciated that these alternative engagement examples maybe used in lieu of or in combination with magnetic engagement. Inexamples without magnets, some advantages include lower cost and lessmanufacturing complexity associated with embedding magnets into plasticmaterial.

For example, FIGS. 34 to 41 illustrate a patient interface 14000according to an example of the present technology. The patient interface14000 includes a frame member 14100, a cushion assembly 14175 includinga seal-forming structure 14200, and an anterior wall member 14300 (shownwithout an elbow) repeatedly engageable with and removably disengageablefrom the cushion assembly 14175 via a mechanical interlock, e.g.,snap-fit connection.

In this example, the frame member 14100 is similar to that shown inFIGS. 31-33 and includes an annular or ring style side wall 14115 withupper headgear connectors 14152 and lower headgear connectors 14120adapted to connect to upper and lower side straps of the positioning andstabilizing structure 3400. The annular side wall 14115 of the framemember 14100 may be releasably connected or interlocked with a retainingportion or frame interface 14250 of the cushion assembly 14175 in anysuitable manner.

The anterior wall member 14300 includes connection port 14302 adapted tobe connected to an elbow or swivel elbow which is connected to the gasdelivery tube 4180. In the illustrated example, the connection port14302 includes grooves 14303 structured to allow a bayonet styleattachment to the elbow. However, it should be appreciated that theelbow may be releasably or permanently connected to the connection port14302 in other suitable manners.

As illustrated, each side of the anterior wall member 14300 includes acantilevered push button 14800 and grooves 14802 along sides of thebutton 14800 that allow the button 14800 to flex with respect to theanterior wall member 14300. Each button 14800 includes a tab or catch14804 (e.g., see FIG. 40 ) along an interior or inwardly facing surfaceof the anterior wall member 14300 that is adapted to engage the cushionassembly 14175 with a snap fit to releasably secure the anterior wallmember 14300 to the cushion assembly 14175.

In the illustrated example, as best shown in FIGS. 40 and 41 , a raisedportion 14820 of the button and webbing 14830 within the grooves 14802along sides of the button is constructed of a soft, tactile material,e.g., TPE. The raised portion 14820 provides a soft tactile feel forease of use and grip, and the webbing 14830 provides seal, soft tactilefeel, and spring (clip return) force. In an example, the raised portion14820 and webbing 14830 are overmolded to the anterior wall member14300.

Each side of a peripheral portion 14105 of the cushion assembly 14175includes a tab or undercut 14110 structured to interlock with arespective tab or catch 14804 of the anterior wall member 14300 toreleasably retain the anterior wall member 14300 to the cushion assembly14175.

In an example, the elbow connected to the connection port 14302 of theanterior wall member 14300 may be used to grip or handle the anteriorwall member 14300 to facilitate engagement/disengagement with thecushion assembly 14175.

In an alternative example, as shown in FIG. 42 , the cantilevered pushbutton 15800 may be provided to the main body 15180 of the cushionassembly 15175, which is structured to interlock with a respective tabor catch on the anterior wall member.

As shown in FIGS. 38 and 39 , a lip seal 14850 (e.g., constructed ofsilicone) is provided along the edge of the peripheral portion 14105defining the void 14102 of the cushion assembly 14175. As illustrated,the lip seal 14850 includes a hollow construction with side walls thatcooperate to define an interior chamber (e.g., see FIG. 39), howeverother suitable sealing configurations are possible. In an example, thelip seal 14850 is overmolded to the main body 14180 of the cushionassembly 14175, e.g., during overmolding of the seal-forming structure14200 to the main body 14180. The lip seal 14850 provides a compressionand pressure assisted/pressure actuated seal between the cushionassembly 14175 and the anterior wall member 14300 when engaged with oneanother. In other words, when air pressure within the plenum chamber3500 increases, the lip seal 14850 is urged against the anterior wallmember 14300 with greater force.

When the anterior wall member 14300 and the cushion assembly 14175 areengaged, the anterior wall member 14300 seals the void 14102 of thecushion assembly 14175 and forms the gas chamber or plenum chamber. Theanterior wall member 14300 is structured to align, seal, and interlockwith main body 14180 of the cushion assembly 14175 (and not the framemember 14100) to allow better tolerance control and avoid headgear straptension forces acting on the anterior wall member 14300. When theanterior wall member 14300 is disengaged from the cushion assembly14175, e.g., see FIG. 37 , the void 14102 of the cushion assembly 14175is sized such that the patient's nose and/or mouth is substantiallyexposed, e.g., to improve patient breathing comfort, improve patientcommunication with bed partner, allow patient to drink/eat/medicate,allow clinician to view seal (from the interior of the patient interfaceprior to commencement of therapy, e.g. the fit of the static seal),and/or facilitate patient/clinician acclimatization to CPAP treatment.

In an example, the frame member 14100 and the anterior wall member 14300may be provided in one size, which may be selectively engageable withmultiple sizes of cushion assemblies 14175, e.g., small, medium, andlarge size cushion assemblies. In an example, regardless of size, thepatient interface provides similar locations for the upper headgearconnectors 14152 (e.g., based on headgear vectors and clearance with thepatient's eyes) and the connection port 14302 for the elbow (e.g., tooptimize gas washout). Also, anthropometrics (e.g., clearance with thepatient's face, nose and/or mouth) and manufacturability (e.g., line ofdraw) may be similar across cushion sizes. For example, the axis of theconnection port 14302 relative to the line of draw (e.g., about 10°) maybe similar across cushion sizes. This may prevent the patient's nosecoming into physical contact with the frame member 14100 and theanterior wall member 14300 when the patient interface is donned.

FIGS. 43 to 52 illustrate a patient interface 16000 according to anotherexample of the present technology. The patient interface 16000 includesa frame member 16100, a cushion assembly 16175 including a seal-formingstructure 16200, and a ring-shaped or disk-shaped anterior wall member16300 (shown without an elbow) repeatedly engageable with and removablydisengageable from the cushion assembly 16175.

In this example, the frame member 16100 is similar to that shown inFIGS. 31-36 and includes an annular or ring style side wall 16115 withupper headgear connectors 16152 and lower headgear connectors 16120adapted to connect to upper and lower side straps of the positioning andstabilizing structure 3400. The annular side wall 16115 of the framemember 16100 may be releasably connected or interlocked with a retainingportion or frame interface 16250 of the cushion assembly 16175 in anysuitable manner.

In an example, the frame member 16100 and the anterior wall member 16300may be provided in one size, which may be selectively engageable withmultiple sizes of cushion assemblies 16175. For example, the cushionassembly 16175 may be provided in three sizes, e.g., a small sizecushion assembly 16175A as shown in FIG. 49A, a medium size cushionassembly 16175B as shown in FIG. 49B, and a large size cushion assembly16175C as shown in FIG. 49C. As illustrated, the different size cushionassemblies include at least one aspect different from one another, e.g.,different heights. As shown in FIG. 48 , each main body 16180 of thedifferent size cushion assemblies includes a retaining portion or frameinterface 16250 that is common or similar for all sizes (e.g., commonengagement surface along an apex and side portions of the main body16180), which allows the one size or common frame member 16100 to beconnected to each of the different size cushion assemblies, i.e., eachcushion assembly includes common frame mating geometry on the frameinterface 16250 for all cushion sizes. Similarly, the peripheral portion16105 defining the void 16102 of each of the different size cushionassemblies includes a similar size and geometry, which allows the onesize or common anterior wall member 16300 to be connected to each of thedifferent size cushion assemblies. FIGS. 50A, 50B, and 50C illustratethe common frame member 16100 and the common anterior wall member 16300engaged with each of the small, medium, and large cushion assemblies16175A, 16175B, 16175C according to an example of the presenttechnology.

The seal-forming structure 16200 is connected to the main body 16180 ofthe cushion assembly 16175, e.g., seal-forming structure 16200 co-moldedto the main body 16180. As shown in FIGS. 51 to 53 , the main body 16180may include a retaining structure 16890 to receive a retaining portion16205 of the seal-forming structure 16200, e.g., and may provide asubstantially continuous internal surface defining the plenum chamber16500. The retaining structure 16890 includes horizontal and verticalwall sections 16892, 16894 that define a space to receive the retainingportion 16205 of the seal-forming structure 16200 therein. In anexample, the retaining structure includes a width w of about 2-5 mm,e.g., 3 mm. The retaining structure 16890 extends around the fullperimeter of the main body 16180 which allows the horizontal wallsection 16892 and its interior seal engaging surface to be maintainedaround the full perimeter for engagement with the retaining portion16205.

The anterior wall member 16300 includes connection port 16302 adapted tobe connected to an elbow or swivel elbow which is connected to the gasdelivery tube 4180. In the illustrated example, the connection port16302 includes grooves 16303 structured to allow a bayonet styleattachment to the elbow. However, it should be appreciated that theelbow may be releasably or permanently connected to the connection port16302 in other suitable manners.

As shown in FIGS. 43, 44, and 46 , at least a peripheral portion 16305of the anterior wall member 16300 is repeatedly engageable with anddisengageable from at least the peripheral portion 16105 of the mainbody 16180 of the cushion assembly 16175. The perimeter, shape, andgeometry of the mating surfaces provided by the peripheral portions16305, 16105 are predetermined to facilitate alignment andmechanical/structural engagement, e.g., clean, smooth, and flat conicalsurfaces with minimal protrusions along leading/trailing edges to avoidinterference with adjacent geometry. Adjacent geometry of the main body16180 may be used as slip surfaces.

The anterior wall member 16300 may be secured and retained to thecushion assembly 16175 in any suitable manner. For example, as shown inFIG. 47 , each side of the peripheral portion 16105 includes a tab 16110associated with a push button 16800, which is structured to engage orinterlock (e.g., with a snap-fit) with a respective tab 16804 of theanterior wall member 16300 to releasably retain the anterior wall member16300 to the cushion assembly 16175.

A lip seal 16850 (e.g., constructed of silicone) is provided, e.g.,overmolded, along the edge of the peripheral portion 16105 defining thevoid 16102 of the cushion assembly 16175. The lip seal 16850 provides acompression and pressure assisted seal between the cushion assembly16175 and the anterior wall member 16300 when engaged with one another.In an example, the lip seal 16850 may extend radially inwardly from theperipheral portion 16105 into the void 16102.

When the anterior wall member 16300 and the cushion assembly 16175 areengaged, the anterior wall member 16300 seals the void 16102 of thecushion assembly 16175 and forms the gas chamber or plenum chamber. Whenthe anterior wall member 16300 is disengaged from the cushion assembly16175, e.g., see FIG. 45 , the void 16102 of the cushion assembly 16175is sized such that at least a portion of the patient's nose and/or mouthis exposed. The void 16102 is sized to be sufficiently larger than theconnection port 13602, e.g., diameter of void 16102 about 35-50 mm,e.g., about 40 mm.

Engagement and Disengagement Process

In one form of the present technology, e.g., as shown in FIG. 17 , theanterior wall member 3300 is engageable with the cushion assembly 3175by posteriorly moving the anterior wall member 3300 towards the cushionassembly 3175 in a direction substantially parallel to the Frankforthorizontal, and the anterior wall member 3300 is disengageable from thecushion assembly 3175 by anteriorly moving the anterior wall member 3300from the cushion assembly 3175 in a direction substantially parallel tothe Frankfort horizontal.

In another example, as shown in FIGS. 18 and 19 a, the anterior wallmember 3300 may be engaged with the cushion assembly 3175 by firstengaging the top magnets 3110 a, 3310 a provided along the apex of therespective peripheral portion 3105, 3305 to locate and align the tip ofthe anterior wall member 3300 with the cushion assembly 3175. Then theanterior wall member 3300 may be pivoting downwardly to engage the lowermagnets 3110 b, 3310 b on opposing, lower sides of the respectiveperipheral portion 3105, 3305 as shown in FIG. 19 b. In such example,the top apex magnets 3110 a, 3310 a may help to engage and locate amechanical engagement, e.g., snap-fit connection, between the anteriorwall member 3300 with the cushion assembly 3175, and the lower sidemagnets 3110 b, 3310 b may help to engage and locate a mechanicalengagement, e.g., snap fit connection, between the anterior wall member3300 with the cushion assembly 3175.

However, it is envisaged that the patient may engage the anterior wallmember 3300 to the cushion assembly 3175 without any pivoting or tiltingof the anterior wall member 3300 downwardly relative to the cushionassembly 3175, or pivoting may be in an upwardly or sideways direction.

In another example, as shown in FIG. 19 c, the anterior wall member 3300may be engaged with the cushion assembly 3175 by first engaging magnets3310, 3110 provided on one lateral side of the anterior wallmember/cushion assembly, and then pivoting the anterior wall member 3300to engage magnets 3310, 3110 provided on the opposing lateral side ofthe anterior wall member/cushion assembly, e.g., left-right attachment.

In an example, the cushion assembly 3175 and frame member 3100 connectedthereto is first positioned against the patient's face using thepositioning and stabilizing structure 3400, and then the anterior wallmember 3300 is engaged with the cushion assembly 3175 to seal the void3102 of the cushion assembly 3175. A sealing lip or pressure activatedseal may provide a pneumatic seal between the anterior wall member 3300and cushion assembly 3175. An exemplary method of donning the patientinterface 3000 includes positioning the cushion assembly 3175 includingthe seal-forming structure 3200 and frame member 3100 connected theretoagainst the patient's face using the positioning and stabilizingstructure 3400 and engaging the anterior wall member 3300 having apredetermined surface area with the cushion assembly 3175 to seal thevoid 3102 of the cushion assembly 3175 and form the gas chamber 3500.

Connection Between Cushion Assembly and Frame Member

In the illustrated example, the cushion assembly 3175 and the framemember 3100 include cooperating retaining structures to connect thecushion assembly 3175 to the frame member 3100. In an example, the framemember 3100 is releasably connectable to the cushion assembly 3175 tofacilitate replacement and/or cleaning, and to allow alternative framemembers and cushion assemblies to be connected to one another. Sucharrangement allows multiple seals (e.g., types and sizes) to be usedwith the patient interface and therefore provide a patient interfacesuitable for Multiple Patient Multiple Use (MPMU) usage situations. Inan alternative example, the frame member 3100 may be permanentlyconnected or integrally formed in one-piece with the cushion assembly3175, e.g., co-molded.

In the illustrated example shown in FIG. 11 a, the frame member 3100includes an open construction with an annular side wall 3115 to receiveand retain the cushion assembly 3175 thereto. The cushion assembly 3175is engaged with the frame member 3100 such that the annular side wall3115 encloses or wraps around the cushion assembly 3175, and at least aportion of the cushion assembly 3175 passes through the frame member3100, i.e., the seal-forming structure 3200 and the peripheral portion3105 of the main body 3180 are provided on opposite sides of the framemember 3100. Such arrangement allows the peripheral portion 3105 of thecushion assembly 3175 to project from the frame member 3100 and besufficiently exposed for engagement with the anterior wall member 3300.Also, connection of the frame member 3100 about the periphery of thecushion assembly 3175 may facilitate a more even transfer of sealingforce to the cushion assembly 3175 from the positioning and stabilisingstructure 3400.

As shown in FIGS. 11 a and 11 b, the annular side wall 3115 includes apair of upper retention features structured to engage or interlock withcorresponding retention features provided to an upper portion (e.g.,apex) of the cushion assembly 3175. In the illustrated example, theupper retention features include a pair of inwardly projecting beads orprotrusions 3117 structured to engage or interlock with correspondingrecesses 3182 provided to the cushion assembly 3175. Also, the cushionassembly 3175 includes elongated protrusions 3184 on opposing, lowersides thereof structured to engage or interlock with opposing lowersides of the annular side wall 3115, e.g., elongated protrusions 3184act as a catch to retain lower sides of the annular side wall 3115 onthe cushion assembly 3175. However, it should be appreciated that thecushion assembly 3175 may be connected or interlocked with the framemember 3100 in other suitable manners.

Connection Port

In the illustrated example, the anterior wall member 3300 comprises aconnection port 3302 for connection to a gas delivery tube. Asillustrated, the connection port 3302 is connected to an elbow or swivelelbow 3600. In an example, as shown in FIGS. 10, 11 a, and 11 b, theelbow 3600 includes first end portion 3602 connected to the connectionport 3302 and a second end portion 3604 adapted to connect to a shorttube 4180 of the air circuit 4170, e.g., via swivel connector 3605. Theswivel elbow 3600 and anterior wall member 3300 may form a permanentassembly, or the swivel elbow 3600 and anterior wall member 3300 may beremovably coupled to one another.

In an alternative example, the cushion assembly 3175 may comprise aconnection port 3302 for connection to a gas delivery tube 4180.

In an alternative example, as shown in FIG. 30 , the gas delivery tube(e.g., short tube 4180) may be directly connected or otherwise providedto the connection port 3302 without the use of an elbow or swivel elbow.For example, the gas delivery tube (e.g., short tube 4180) may bedirectly connected to the connection port 3302 of the anterior wallmember 3300. The gas delivery tube 4180 may be permanently or removablyconnected to the connection port 3302. Permanent connection may be byway of overmolding or mechanical interlock.

Vent

In one form of the present technology, the patient interface 3000 mayinclude a vent 3700 constructed and arranged to allow for the washout ofexhaled air (including carbon dioxide). The vent 3700 is not bulky,i.e., not thick or protrude significantly in the anterior and/orposterior direction. The vent 3700 directs exhaust air away from thecushion assembly 3175 and plenum chamber 3500.

Referring to FIGS. 10, 11 a, and 11 b, one form of vent 3700 inaccordance with the present technology comprises a plurality of verysmall holes 3705, in other words, a multi-hole vent 3700. Two or moremulti-hole vents 3700 may be provided to the patient interface 3000.

In the illustrated example, the vent 3700 is integrated into theanterior wall member 3300 and is implemented as an array of at leastthirty (30) vent holes, e.g., at least 40 vent holes 3705, that ringaround the connection port 3302, e.g., see FIGS. 10, 11 a, and 11 b. Inother words, the vent 3700 has a substantially circular shape. That is,the anterior wall member 3300 has a multi-hole vent 3700 radiallydisposed around the connection port 3302 connected to the swivel elbow3600. The individual vent holes 3705 are shaped so as to diffuse theexhaust air (i.e., not directional) thereby reducing the exhaust noiseand effects of “air jetting”, whilst providing adequate CO₂ washout, forexample, tapered vent holes 3705.

In an alternative example, at least one vent 3700 may be provided on theswivel elbow 3600 or the cushion assembly 3175 to allow the washout ofair.

In another example, the vent 3700 may be made from a textile formed ofinterlaced plastic fibers, e.g., mesh vent.

Seal-Forming Structure

In one form of the present technology, the seal-forming structure 3200is permanently connected to the main body 3180 of the cushion assembly3175, e.g., the seal-forming structure 3200 is co-molded to the mainbody 3180.

In another form of the present technology, the seal-forming structure3200 may include a retaining structure to connect the seal-formingstructure 3200 to the main body 3180. For example, the retainingstructure (e.g., constructed of a relatively hard plastic material) maybe in the form of a retaining clip structured to releasably connect tothe main body 3180 with a snap-fit and provide the seal-formingstructure 3200 with a hard-to hard connection with the main body 3180.

In the example shown in FIGS. 4 to 14, 17, 18, 20 a, 20 b, and 21, theseal-forming structure 3200 is of a first type structured to serve thepatient's nose and mouth. For example, the seal-forming structure 3200may be a full-face/oro-nasal cushion structured to form a seal aroundthe patient's nose and mouth.

In an alternative example, the seal-forming structure 3200 is of asecond type structured to only serve the patient's nares. For example,the seal-forming structure 3200 may be a nasal cushion or nasal cradlestructured to form a seal around both nares without being partiallylocated inside the nose. In another example, the seal-forming structure3200 may include nasal pillows or nasal prongs structured to form a sealsurrounding or with the patient's nares (e.g., see FIGS. 26 to 29 ).

For example, FIGS. 24 a and 24 b illustrate a patient interface 7000including a frame member 7100, a seal-forming member 7200 (e.g., nasalcushion) co-molded or otherwise attached to the frame member 7100, andan anterior wall member 7300 (with elbow 7600) magnetically attachableto the frame member 7100 via respective magnets 7310, 7110. In anexample, as shown in FIG. 24 b, a cushion clip 7205 is provided (e.g.,co-molded) to the seal-forming member 7200, which cushion clip 7205allows the seal-forming member 7200 to be releasably attached to theframe member 7100. In an example, the elbow 7600 may swivel and/or flexrelative to the anterior wall member 7300. In an alternative form, thegas delivery tube may be coupled directly to the anterior wall member7300 without an elbow. In this example, the seal-forming member 7200 isin the form of a nasal cushion structured to form a seal around thepatient's nose. Also, the patient interface 7000 may be structured tohouse an optional and replaceable heat and moisture exchanger (HME/HMX)cartridge 7750 to provide sufficient heat and humidity to the patientduring therapy.

In another example, as shown in FIGS. 25 a and 25 b, the frame member7100 and the anterior wall member 7300 may include a generally circularinterface, e.g., frame member 7100 and anterior wall member 7300 providegenerally circular magnets 7110, 7310 which provide a magnetic ringconnection that allows swiveling between the frame member 7100 and theanterior wall member 7300. In an example, a cushion clip 7205 may beprovided (e.g., co-molded) to the seal-forming member 7200, whichcushion clip 7205 allows the seal-forming member 7200 to be releasablyattached to the frame member 7100. However, it should be appreciatedthat the seal-forming member 7200 may be attached to the frame member7100 in other suitable manners.

FIGS. 26 a and 26 b show another example of a patient interface 8000including a frame member 8100, a seal-forming member 8200 co-molded orotherwise attached to the frame member 8100, and an anterior wall member8300 (with elbow 8600) magnetically attachable to the frame member 8100via respective magnets 8310, 8110. In this example, the seal-formingmember 8200 is in the form of nasal pillows structured to form a sealsurrounding or with the patient's nares. In an example, a cushion clip8205 may be provided (e.g., co-molded) to the seal-forming member 8200,which cushion clip 8205 allows the seal-forming member 8200 to bereleasably attached to the frame member 8100. However, it should beappreciated that the seal-forming member 8200 may be attached to theframe member 8100 in other suitable manners.

As shown in FIGS. 27 and 28 , the frame member 8100 may be attachable tothe anterior wall member 8300 in other manners, e.g., mechanicalinterlock used in combination with magnetic engagement. In FIG. 27 , asnap-fit connector 8311 is used along with magnet 8310 to attach theanterior wall member 8300 to the frame member 8100. In FIG. 28 , analternative snap-fit connector 8313 is used along with magnet 8310 toattach the anterior wall member 8300 to the frame member 8100. In eachexample, a cushion clip 8205 may be provided (e.g., co-molded) to theseal-forming member 8200, which cushion clip 8205 allows theseal-forming member 8200 to be releasably attached to the frame member8100. However, it should be appreciated that the seal-forming member8200 may be attached to the frame member 8100 in other suitable manners.

In yet another example, as shown in FIG. 29 , each connector may providea mechanical interlock along with a magnet. As illustrated, the anteriorwall member 8300 includes a snap-fit connector 8315 provided with amagnet 8310, and the frame member 8100 includes a connector providedwith a magnet 8110. In an example, a cushion clip 8205 may be provided(e.g., co-molded) to the seal-forming member 8200, which cushion clip8205 allows the seal-forming member 8200 to be releasably attached tothe frame member 8100. However, it should be appreciated that theseal-forming member 8200 may be attached to the frame member 8100 inother suitable manners. In another example, the snap-fit connector 8315and the connector of the frame member 8100 may not be provided withmagnets, and the anterior wall member 8300 may be secured to the framemember 8100 only mechanically.

In one form of the present technology, the seal-forming structure 3200provides a sealing-forming surface, and may additionally provide acushioning function. A seal-forming structure 3200 of the non-invasivepatient interface 3000 in accordance with the present technology may beconstructed from a soft, flexible, resilient material such as silicone.However, the seal-forming structure 3200 may comprise other materials,e.g., foam and/or gel and/or low durometer silicone.

In one form of the present technology, the patient interface 3000 mayprovide a modular system including a single anterior wall member orfascia which is attachable to or otherwise structured to interface withframe members, cushion assemblies, and/or seal-forming structures ofmultiple types, sizes and/or interface types. For example, cushionassemblies having different seal-forming structures may be attachable toa common frame member and also allow attachment to the single anteriorwall member or fascia.

Forehead Support

In one form of the present technology, the patient interface 3000includes a forehead support. In the illustrated example shown in FIGS.4-14 , the frame member 3100 includes a forehead support 3150.

The forehead support 3150 includes upper headgear connectors 3152adapted to connect to upper side straps 3402 of the positioning andstabilizing structure 3400 (e.g., see FIGS. 4 to 9 ). The frame member3100 comprises lower headgear connectors 3120 adapted to connect tolower side straps 3404 of the positioning and stabilizing structure 3400(e.g., see FIGS. 4 to 9 ).

In one alternative form, the patient interface 3000 does not include aforehead support. For example, FIGS. 23 to 28 illustrate examples ofpatient interfaces that do not include a forehead support.

For example, FIG. 23 illustrates a patient interface 6000 including aframe member 6100, a cushion assembly 6175 including a seal-formingmember 6200 replaceably attached to the frame member 6100 via aretaining structure 6250, and an anterior wall member 6300 (with elbow6600) magnetically attachable to the frame member 6100 via respectivemagnets 6310, 6110. In this example, the frame member 6100 includesupper headgear connectors 6152 and lower headgear connectors 6120adapted to connect to upper and lower side straps 3402, 3404 of thepositioning and stabilizing structure 3400.

FIGS. 31 to 33 show an alternative example in which an alternative framemember 13100 is provided to the cushion assembly 3175. In this example,the frame member 13100 does not include a forehead support. Asillustrated, the frame member 13100 includes an annular side wall 13115with upper headgear connectors 13152 and lower headgear connectors 13120adapted to connect to upper and lower side straps of the positioning andstabilizing structure 3400. Similar to the example described above, theframe member 13100 is releasably connected to the cushion assembly 3175,e.g., by engaging a pair of inwardly projecting beads or protrusions13117 with corresponding recesses 3182 provided to the cushion assembly3175 and engaging lower sides of the annular side wall 13115 withrespective protrusions 3184 provided to the cushion assembly 3175.However, it should be appreciated that the cushion assembly 3175 may beconnected or interlocked with the frame member 13100 in other suitablemanners.

As best shown in FIG. 33 , the peripheral portion 3105 of the cushionassembly 3175 projects from the frame member 13100 to be sufficientlyexposed for releasable engagement with the anterior wall member 3300.

Positioning and Stabilising Structure

Note that in one form of the present technology, a number of structuralfeatures form part of a positioning and stabilising structure 3400,e.g., a headgear assembly (which may be referred to simply as headgear).In an alternative form of the present technology, one or more of thosefeatures are located on or permanently attached to the frame 3100 orretaining structure of the cushion assembly.

The seal-forming structure 3200 of the patient interface 3000 of thepresent technology may be held in sealing position in use by thepositioning and stabilising structure 3400 (FIGS. 4 to 9 ). In one form,the positioning and stabilising structure 3400 comprises headgear. Itshould be appreciated that the positioning and stabilising structure3400 may, in one form of the technology, be referred to as headgear.

The positioning and stabilising structure 3400 may comprise two pairs ofside straps, i.e., a pair of upper side straps 3402 and a pair of lowerside straps 3404, connected to a circular crown strap 3406 thatencapsulates the crown of the patient's head. Headgear straps to anchorand maintain the cushion assembly on the patient's face provides asuitable arrangement to comfortably handle tube torque from the gasdelivery tube.

The upper side straps 3402 connect to the upper headgear connectors 3152of the forehead support 3150 and the lower side straps 3404 connect tothe lower headgear connectors 3120 of the frame member 3100. The sidestraps 3402, 3404 may include an adjustable hook and loop (Velcro™)connection mechanism, e.g., Velcro™-like hook tabs, to facilitateconnection and/or adjustment to the headgear connectors 3152, 3120.

3.4 Pap Device 4000

A PAP device 4000 in accordance with one aspect of the presenttechnology comprises mechanical and pneumatic components 4100,electrical components 4200 and is programmed to execute one or morealgorithms. The PAP device may have an external housing 4010, formed intwo parts, an upper portion 4012 of the external housing 4010, and alower portion 4014 of the external housing 4010. In alternative forms,the external housing 4010 may include one or more panel(s) 4015. The PAPdevice 4000 may comprise a chassis 4016 that supports one or moreinternal components of the PAP device 4000. In one form a pneumaticblock 4020 is supported by, or formed as part of the chassis 4016. ThePAP device 4000 may include a handle 4018.

The pneumatic path of the PAP device 4000 may comprise an inlet airfilter 4112, an inlet muffler, a controllable pressure device capable ofsupplying air at positive pressure (e.g., a controllable blower 4142),and an outlet muffler. One or more pressure sensors and flow sensors maybe included in the pneumatic path.

The pneumatic block 4020 may comprise a portion of the pneumatic paththat is located within the external housing 4010.

The PAP device 4000 may have an electrical power supply 4210 and one ormore input devices 4220. Electrical components 4200 may be mounted on asingle Printed Circuit Board Assembly (PCBA) 4202. In an alternativeform, the PAP device 4000 may include more than one PCBA 4202.

3.4.1 PAP Device Mechanical & Pneumatic Components 4100 3.4.1.1 AirFilter(s) 4110

A PAP device 4000 in accordance with one form of the present technologymay include an air filter 4110, or a plurality of air filters 4110.

In one form, an inlet air filter 4112 is located at the beginning of thepneumatic path upstream of a controllable blower 4142. See FIG. 3 c.

In one form, an outlet air filter 4114, for example an antibacterialfilter, is located between an outlet of the pneumatic block 4020 and apatient interface 3000. See FIG. 3 c.

3.4.1.2 Pressure Device 4140

In a form of the present technology, a pressure device for producing aflow of air at positive pressure is a controllable blower 4142. Forexample the blower 4142 may include a brushless DC motor with one ormore impellers housed in a volute. The blower 4142 may be capable ofdelivering a supply of air, for example about 120 litres/minute, at apositive pressure in a range from about 4 cmH₂O to about 20 cmH₂O, or inother forms up to about 30 cmH₂O.

3.5 Humidifier 5000 3.5.1 Humidifier Overview

In one form of the present technology there is provided a humidifier5000, as shown in FIG. 3 b, that may comprise a water reservoir and aheating plate.

3.6 Glossary

In certain forms of the present technology, one or more of the followingdefinitions may apply. In other forms of the present technology,alternative definitions may apply.

3.6.1 General

Air: Air will be taken to include breathable gases, for example air withsupplemental oxygen.

Continuous Positive Airway Pressure (CPAP): CPAP treatment will be takento mean the application of a supply of air or breathable gas to theentrance to the airways at a pressure that is continuously positive withrespect to atmosphere, and preferably approximately constant through arespiratory cycle of a patient. In some forms, the pressure at theentrance to the airways will vary by a few centimeters of water within asingle respiratory cycle, for example being higher during inhalation andlower during exhalation. In some forms, the pressure at the entrance tothe airways will be slightly higher during exhalation, and slightlylower during inhalation. In some forms, the pressure will vary betweendifferent respiratory cycles of the patient, for example being increasedin response to detection of indications of partial upper airwayobstruction, and decreased in the absence of indications of partialupper airway obstruction.

3.6.2 Aspects of PAP Devices

Air circuit: A conduit or tube constructed and arranged in use todeliver a supply of air or breathable gas between a PAP device and apatient interface. In particular, the air circuit may be in fluidconnection with the outlet of the pneumatic block and the patientinterface. The air circuit may be referred to as air delivery tube. Insome cases there may be separate limbs of the circuit for inhalation andexhalation. In other cases a single limb is used.

Blower or flow generator: A device that delivers a flow of air at apressure above ambient pressure.

Controller: A device, or portion of a device that adjusts an outputbased on an input. For example one form of controller has a variablethat is under control—the control variable—that constitutes the input tothe device. The output of the device is a function of the current valueof the control variable, and a set point for the variable. Aservo-ventilator may include a controller that has ventilation as aninput, a target ventilation as the set point, and level of pressuresupport as an output. Other forms of input may be one or more of oxygensaturation (SaO2), partial pressure of carbon dioxide (PCO2), movement,a signal from a photoplethysmogram, and peak flow. The set point of thecontroller may be one or more of fixed, variable or learned. Forexample, the set point in a ventilator may be a long term average of themeasured ventilation of a patient. Another ventilator may have aventilation set point that changes with time. A pressure controller maybe configured to control a blower or pump to deliver air at a particularpressure.

Therapy: Therapy in the present context may be one or more of positivepressure therapy, oxygen therapy, carbon dioxide therapy, control ofdead space, and the administration of a drug.

Positive Airway Pressure (PAP) device: A device for providing a supplyof air at positive pressure to the airways.

3.6.3 Anatomy of the Face

Ala: the external outer wall or “wing” of each nostril (plural: alar)

Alare: The most lateral point on the nasal ala.

Alar curvature (or alar crest) point: The most posterior point in thecurved base line of each ala, found in the crease formed by the union ofthe ala with the cheek.

Auricula or Pinna: The whole external visible part of the ear.

(nose) Bony framework: The bony framework of the nose comprises thenasal bones, the frontal process of the maxillae and the nasal part ofthe frontal bone.

(nose) Cartilaginous framework: The cartilaginous framework of the nosecomprises the septal, lateral, major and minor cartilages.

Columella: the strip of skin that separates the nares and which runsfrom the pronasale to the upper lip.

Columella angle: The angle between the line drawn through the midpointof the nostril aperture and a line drawn perpendicular to the Frankfurthorizontal while intersecting subnasale.

Frankfort horizontal plane: A line extending from the most inferiorpoint of the orbital margin to the left tragion. The tragion is thedeepest point in the notch superior to the tragus of the auricle.

Glabella: Located on the soft tissue, the most prominent point in themidsagittal plane of the forehead.

Lateral nasal cartilage: A generally triangular plate of cartilage. Itssuperior margin is attached to the nasal bone and frontal process of themaxilla, and its inferior margin is connected to the major alarcartilage.

Major alar cartilage: A plate of cartilage lying below the lateral nasalcartilage. It is curved around the anterior part of the naris. Itsposterior end is connected to the frontal process of the maxilla by atough fibrous membrane containing three or four minor cartilages of theala.

Nares (Nostrils): Approximately ellipsoidal apertures forming theentrance to the nasal cavity. The singular form of nares is naris(nostril). The nares are separated by the nasal septum.

Naso-labial sulcus or Naso-labial fold: The skin fold or groove thatruns from each side of the nose to the corners of the mouth, separatingthe cheeks from the upper lip.

Naso-labial angle: The angle between the columella and the upper lip,while intersecting subnasale.

Otobasion inferior: The lowest point of attachment of the auricle to theskin of the face.

Otobasion superior: The highest point of attachment of the auricle tothe skin of the face.

Pronasale: the most protruded point or tip of the nose, which can beidentified in lateral view of the rest of the portion of the head.

Philtrum: the midline groove that runs from lower border of the nasalseptum to the top of the lip in the upper lip region.

Pogonion: Located on the soft tissue, the most anterior midpoint of thechin.

Ridge (nasal): The nasal ridge is the midline prominence of the nose,extending from the Sellion to the Pronasale.

Sagittal plane: A vertical plane that passes from anterior (front) toposterior (rear) dividing the body into right and left halves.

Sellion: Located on the soft tissue, the most concave point overlyingthe area of the frontonasal suture.

Septal cartilage (nasal): The nasal septal cartilage forms part of theseptum and divides the front part of the nasal cavity.

Subalare: The point at the lower margin of the alar base, where the alarbase joins with the skin of the superior (upper) lip.

Subnasal point: Located on the soft tissue, the point at which thecolumella merges with the upper lip in the midsagittal plane.

Supramentale: The point of greatest concavity in the midline of thelower lip between labrale inferius and soft tissue pogonion.

3.6.4 Anatomy of the Skull

Frontal bone: The frontal bone includes a large vertical portion, thesquama frontalis, corresponding to the region known as the forehead.

Mandible: The mandible forms the lower jaw. The mental protuberance isthe bony protuberance of the jaw that forms the chin.

Maxilla: The maxilla forms the upper jaw and is located above themandible and below the orbits. The frontal process of the maxillaprojects upwards by the side of the nose, and forms part of its lateralboundary.

Nasal bones: The nasal bones are two small oblong bones, varying in sizeand form in different individuals; they are placed side by side at themiddle and upper part of the face, and form, by their junction, the“bridge” of the nose.

Nasion: The intersection of the frontal bone and the two nasal bones, adepressed area directly between the eyes and superior to the bridge ofthe nose.

Occipital bone: The occipital bone is situated at the back and lowerpart of the cranium. It includes an oval aperture, the foramen magnum,through which the cranial cavity communicates with the vertebral canal.The curved plate behind the foramen magnum is the squama

Parietal bones: The parietal bones are the bones that, when joinedtogether, form the roof and sides of the cranium.

Temporal bones: The temporal bones are situated on the bases and sidesof the skull, and support that part of the face known as the temple.

Zygomatic bones: The face includes two zygomatic bones, located in theupper and lateral parts of the face and forming the prominence of thecheek.

3.6.5 Anatomy of the Respiratory System

Diaphragm: A sheet of muscle that extends across the bottom of the ribcage. The diaphragm separates the thoracic cavity, containing the heart,lungs and ribs, from the abdominal cavity. As the diaphragm contractsthe volume of the thoracic cavity increases and air is drawn into thelungs.

Larynx: The larynx, or voice box houses the vocal folds and connects theinferior part of the pharynx (hypopharynx) with the trachea.

Lungs: The organs of respiration in humans. The conducting zone of thelungs contains the trachea, the bronchi, the bronchioles, and theterminal bronchioles. The respiratory zone contains the respiratorybronchioles, the alveolar ducts, and the alveoli.

Nasal cavity: The nasal cavity (or nasal fossa) is a large air filledspace above and behind the nose in the middle of the face. The nasalcavity is divided in two by a vertical fin called the nasal septum. Onthe sides of the nasal cavity are three horizontal outgrowths callednasal conchae (singular “concha”) or turbinates. To the front of thenasal cavity is the nose, while the back blends, via the choanae, intothe nasopharynx.

Pharynx: The part of the throat situated immediately inferior to (below)the nasal cavity, and superior to the oesophagus and larynx. The pharynxis conventionally divided into three sections: the nasopharynx(epipharynx), the oropharynx (mesopharynx), and the laryngopharynx(hypopharynx).

3.6.6 Materials

Silicone or Silicone Elastomer: A synthetic rubber. In thisspecification, a reference to silicone is a reference to liquid siliconerubber (LSR) or a compression molded silicone rubber (CMSR). One form ofcommercially available LSR is SILASTIC (included in the range ofproducts sold under this trademark), manufactured by Dow Corning.Another manufacturer of LSR is Wacker. Unless otherwise specified to thecontrary, a preferred form of LSR has a Shore A (or Type A) indentationhardness in the range of about 35 to about 45 as measured using ASTMD2240.

Polycarbonate: a typically transparent thermoplastic polymer ofBisphenol-A Carbonate.

3.6.7 Aspects of a Patient Interface

Anti-asphyxia valve (AAV): The component or sub-assembly of a masksystem that, by opening to atmosphere in a failsafe manner, reduces therisk of excessive CO₂ rebreathing by a patient.

Elbow: A conduit that directs an axis of flow or air to change directionthrough an angle. In one form, the angle may be approximately 90degrees. In another form, the angle may be less than 90 degrees. Theconduit may have an approximately circular cross-section. In anotherform the conduit may have an oval or rectangular cross-section.

Frame: Frame will be taken to mean a mask structure that bears the loadof tension between two or more points of connection with a headgear. Amask frame may be a non-airtight load bearing structure in the mask.However, some forms of mask frame may also be air-tight.

Functional dead space: The functional dead space refers to at least oneregion within a breathing circuit where a patient's exhalate may collectsuch that the normal flow of gas within the breathing circuit cannoteffectively flush the exhalate from the breathing circuit.

Headgear: Headgear will be taken to mean a form of positioning andstabilizing structure designed for use on a head. Preferably theheadgear comprises a collection of one or more struts, ties andstiffeners configured to locate and retain a patient interface inposition on a patient's face for delivery of respiratory therapy. Someties are formed of a soft, flexible, elastic material such as alaminated composite of foam and fabric.

Membrane: Membrane will be taken to mean a typically thin element thathas, preferably, substantially no resistance to bending, but hasresistance to being stretched.

Plenum chamber: a mask plenum chamber will be taken to a mean portion ofa patient interface having walls enclosing a volume of space, the volumehaving air therein pressurised above atmospheric pressure in use. Ashell may form part of the walls of a mask plenum chamber. In one form,a region of the patient's face forms one of the walls of the plenumchamber.

Seal: The noun form (“a seal”) will be taken to mean a structure orbarrier that intentionally resists the flow of air through the interfaceof two surfaces. The verb form (“to seal”) will be taken to mean toresist a flow of air.

Shell: A shell will preferably be taken to mean a curved structurehaving bending, tensile and compressive stiffness, for example, aportion of a mask that forms a curved structural wall of the mask.Preferably, compared to its overall dimensions it is relatively thin. Insome forms, a shell may be faceted. Preferably such walls are airtight,although in some forms they may not be airtight.

Stiffener: A stiffener will be taken to mean a structural componentdesigned to increase the bending resistance of another component in atleast one direction.

Strut: A strut will be taken to be a structural component designed toincrease the compression resistance of another component in at least onedirection.

Swivel: (noun) A subassembly of components configured to rotate about acommon axis, preferably independently, preferably under low torque. Inone form, the swivel may be constructed to rotate through an angle of atleast 360 degrees. In another form, the swivel may be constructed torotate through an angle less than 360 degrees. When used in the contextof an air delivery conduit, the sub-assembly of components preferablycomprises a matched pair of cylindrical conduits. Preferably there islittle or no leak flow of air from the swivel in use.

Tie: A tie will be taken to be a structural component designed to resisttension.

Vent: (noun) the structure that allows a deliberate controlled rate leakof air from an interior of the mask, or conduit to ambient air, to allowwashout of exhaled carbon dioxide (CO₂) and supply of oxygen (O₂).

3.6.8 Terms Used in Relation to Patient Interface

Curvature (of a surface): A region of a surface having a saddle shape,which curves up in one direction and curves down in a differentdirection, will be taken to have a negative curvature. A region of asurface having a dome shape, which curves the same way in two principledirections, will be taken to have a positive curvature. A flat surfacewill be taken to have zero curvature.

Floppy: A quality of a material, structure or composite that is thecombination of features of:

Readily conforming to finger pressure.

Unable to retain its shape when caused to support its own weight.

Not rigid.

Able to be stretched or bent elastically with little effort.

The quality of being floppy may have an associated direction, hence aparticular material, structure or composite may be floppy in a firstdirection, but stiff or rigid in a second direction, for example asecond direction that is orthogonal to the first direction.

Resilient: Able to deform substantially elastically, and to releasesubstantially all of the energy upon unloading, within a relativelyshort period of time such as 1 second.

Rigid: Not readily deforming to finger pressure, and/or the tensions orloads typically encountered when setting up and maintaining a patientinterface in sealing relationship with an entrance to a patient'sairways.

Semi-rigid: means being sufficiently rigid to not substantially distortunder the effects of mechanical forces typically applied during positiveairway pressure therapy.

3.7 Other Remarks

Unless the context clearly dictates otherwise and where a range ofvalues is provided, it is understood that each intervening value, to thetenth of the unit of the lower limit, between the upper and lower limitof that range, and any other stated or intervening value in that statedrange is encompassed within the technology. The upper and lower limitsof these intervening ranges, which may be independently included in theintervening ranges, are also encompassed within the technology, subjectto any specifically excluded limit in the stated range. Where the statedrange includes one or both of the limits, ranges excluding either orboth of those included limits are also included in the technology.

Furthermore, where a value or values are stated herein as beingimplemented as part of the technology, it is understood that such valuesmay be approximated, unless otherwise stated, and such values may beutilized to any suitable significant digit to the extent that apractical technical implementation may permit or require it.

It must be noted that as used herein and in the appended claims, thesingular forms “a”, “an”, and “the” include their plural equivalents,unless the context clearly dictates otherwise.

Moreover, in interpreting the disclosure, all terms should beinterpreted in the broadest reasonable manner consistent with thecontext. In particular, the terms “comprises” and “comprising” should beinterpreted as referring to elements, components, or steps in anon-exclusive manner, indicating that the referenced elements,components, or steps may be present, or utilized, or combined with otherelements, components, or steps that are not expressly referenced.

Although the technology herein has been described with reference toparticular examples, it is to be understood that these examples aremerely illustrative of the principles and applications of thetechnology. In some instances, the terminology and symbols may implyspecific details that are not required to practice the technology. Forexample, although the terms “first” and “second” may be used, unlessotherwise specified, they are not intended to indicate any order but maybe utilised to distinguish between distinct elements. Furthermore,although process steps in the methodologies may be described orillustrated in an order, such an ordering is not required. Those skilledin the art will recognize that such ordering may be modified and/oraspects thereof may be conducted concurrently or even synchronously.

It is therefore to be understood that numerous modifications may be madeto the illustrative examples and that other arrangements may be devisedwithout departing from the spirit and scope of the technology.

While the present technology has been described in connection with whatare presently considered to be the most practical and preferredexamples, it is to be understood that the technology is not to belimited to the disclosed examples, but on the contrary, is intended tocover various modifications and equivalent arrangements included withinthe spirit and scope of the technology. Also, the various examplesdescribed above may be implemented in conjunction with other examples,e.g., aspects of one example may be combined with aspects of anotherexample to realize yet other examples. Further, each independent featureor component of any given assembly may constitute an additional example.

3.8 REFERENCE SIGNS LIST Number Feature Item  302 conventionalconnection port 1000 patient 1100 bed partner 3000 patient interface3100 frame member 3102 void 3104 anterior facing surface 3105 peripheralportion 3110 magnet 3115 annular side wall 3117 beads 3120 lowerheadgear connector 3150 forehead support 3152 upper headgear connector3175 cushion assembly 3180 main body 3182 recesses 3184 protrusions 3200seal-forming structure 3300 anterior wall member 3302 connection port3303 posterior facing surface 3305 peripheral portion 3310 magnet 3400positioning and stabilizing structure 3402 upper side straps 3404 lowerside straps 3406 crown strap 3500 plenum chamber 3600 swivel elbow 3602first end portion 3604 second end portion 3605 swivel connector 3700vent 3705 vent holes 3750 HME/HMX cartridge 4000 PAP device 4010 housing4012 upper portion 4014 lower portion 4015 panels 4016 chassis 4018handle 4020 pneumatic block 4100 mechanical and pneumatic components4110 filter 4112 filter 4114 filter 4142 blower 4170 gas delivery tube4180 gas delivery tube 4190 adaptor 4200 electrical components 4202 PCBA4210 power supply 4220 input devices 5000 humidifier 6000 patientinterface 6100 frame member 6110 magnet 6120 lower headgear connectors6152 upper headgear connectors 6175 cushion assembly 6200 seal-formingmember 6250 retaining structure 6300 anterior wall member 6310 magnet6600 elbow 7000 patient interface 7100 frame member 7110 magnet 7200seal-forming member 7205 cushion clip 7300 anterior wall member 7310magnet 7600 elbow 7750 HME/HMX cartridge 8000 patient interface 8100frame member 8110 magnet 8200 seal-forming member 8205 cushion clip 8300anterior wall member 8310 magnet 8311 snap-fit connector 8313 snap-fitconnector 8315 snap-fit connector 8600 elbow 13100  frame member 13115 annular side wall 13117  beads 13120  lower headgear connectors 13152 upper headgear connectors 14000  patient interface 14100  frame member14102  void 14105  peripheral portion 14110  tab or catch 14115  annularside wall 14120  lower headgear connectors 14152  upper headgearconnectors 14175  cushion assembly 14180  main body 14200  seal-formingstructure 14250  retaining portion 14300  anterior wall member 14302 connection port 14303  grooves 14800  push button 14802  grooves 14804 tab or catch 14820  raised portion 14830  webbing 14850  lip seal 15175 cushion assembly 15180  main body 15800  push button 16000  patientinterface 16100  frame member 16102  void 16105  peripheral portion16110  tab 16115  annular side wall 16120  lower headgear connectors16152  upper headgear connectors 16175  cushion assembly  16175A smallcushion assembly  16175B medium cushion assembly  16175C large cushionassembly 16180  main body 16200  seal-forming structure 16205  retainingportion 16250  retaining portion 16300  anterior wall member 16302 connection port 16303  grooves 16305  peripheral portion 16800  pushbutton 16804  tab 16850  lip seal 16890  retaining structure 16892 horizontal wall section 16894  vertical wall section

1. A patient interface for delivery of a supply of pressurised air orbreathable gas to an entrance of a patient's airways, comprising: aframe member including connectors operatively attachable to apositioning and stabilizing structure; a cushion assembly provided tothe frame member, the cushion assembly including a seal-formingstructure and a void defined by an anterior surface of the cushionassembly; and an anterior wall member repeatedly engageable with anddisengageable from the cushion assembly, the anterior wall member havinga predetermined surface area to seal the void of the cushion assemblyand form a gas chamber when the anterior wall member and the cushionassembly are engaged; wherein the void of the cushion assembly is sizedsuch that the patient's nose and/or mouth is substantially exposed whenthe anterior wall member is disengaged from the cushion assembly therebyimproving breathing comfort of the patient.
 2. The patient interface ofclaim 1, wherein either the anterior wall member or the cushion assemblycomprises a connection port for connection to a gas delivery tube. 3.The patient interface of claim 1, wherein the anterior wall membercomprises a connection port for connection to a gas delivery tube. 4.The patient interface of claim 1, wherein the seal-forming structure ofthe cushion assembly is a first type and the anterior wall member isadditionally engageable with a seal-forming structure of a cushionassembly of a second type.
 5. The patient interface of claim 4, whereinthe first type of seal-forming structure serves the patient's nose andmouth and the second type of seal-forming structure only serves thepatient's nares.
 6. The patient interface of claim 1, wherein at least aperipheral portion of the anterior wall member is repeatedly engageablewith and disengageable from at least a peripheral portion of the cushionassembly.
 7. The patient interface of claim 6, wherein the peripheralportion of the anterior wall member and the peripheral portion of thecushion assembly are rigid such that engagement between the peripheralportion of the anterior wall member and the peripheral portion of thecushion assembly is not caused by material deformation of the anteriorwall member and/or the cushion assembly.
 8. The patient interface ofclaim 7, wherein the peripheral portion of the anterior wall member andthe peripheral portion of the cushion assembly are magneticallyengageable.
 9. The patient interface of claim 8, wherein the peripheralportion of the anterior wall member and the peripheral portion of thecushion assembly has at least one magnet.
 10. The patient interface ofclaim 9, wherein the at least one magnet is a permanent magnet or anelectromagnet.
 11. The patient interface of claim 8, wherein magneticengagement of the peripheral portion of the anterior wall member and theperipheral portion of the cushion assembly causes a flow generator tosupply pressurised respiratory gas to the patient interface via a gasdelivery tube, and when the anterior wall member and cushion assemblyare disengaged the flow generator ceases the supply of pressurisedrespiratory gas to the patient interface.
 12. The patient interface ofclaim 1, further comprising at least one vent provided on the anteriorwall member to allow the washout of exhaled carbon dioxide.
 13. Thepatient interface of claim 2, wherein the connection port is connectedto a swivel elbow operatively connected to the gas delivery tube. 14.The patient interface of claim 13, further comprising at least one ventprovided on the swivel elbow to allow the washout of exhaled carbondioxide.
 15. The patient interface of claim 1, wherein the cushionassembly is releasably connected to the frame member.
 16. The patientinterface of claim 15, wherein the frame member includes an annular sidewall that encloses or wraps around the cushion assembly.
 17. The patientinterface of claim 15, wherein the cushion assembly projects from theframe member so as to be exposed for engagement with the anterior wallmember.
 18. The patient interface of claim 15, wherein the frame memberincludes retention features structured to engage or interlock withcorresponding retention features provided to the cushion assembly. 19.The patient interface of claim 1, wherein the frame member comprises aforehead support.
 20. The patient interface of claim 2, wherein the gasdelivery tube is permanently connected to the connection port.